WASHINGTON — Judge Brett M. Kavanaugh, the front-runner to replace Justice Anthony M. Kennedy on the Supreme Court, once argued that President Bill Clinton could be impeached for lying to his staff and misleading the public, a broad definition of obstruction of justice that would be damaging if applied to President Trump in the Russia investigation.

Judge Kavanaugh’s arguments — expressed in the report of the independent counsel, Kenneth W. Starr, which he co-wrote nearly 20 years ago — have been cited in recent days by Republicans with reservations about him and have raised concerns among some people close to Mr. Trump. But Judge Kavanaugh has reconsidered some of his views since then, and there is no evidence that they have derailed his candidacy.

A federal appeals judge and onetime law clerk for Justice Kennedy, Judge Kavanaugh, 53, is one of only two or three candidates Mr. Trump is still considering for the opening on the court, people familiar with his thinking said. The others are Judge Raymond M. Kethledge of the Sixth Circuit and Judge Amy Coney Barrett of the Seventh Circuit. Mr. Trump said on Thursday that he would announce his choice at 9 p.m. Monday, a day before leaving for Europe.

“I have it down to four people, and I think of the four people, I have it down to three or two,” he told reporters on Air Force One as he flew to a rally in Montana. “I think they’re all outstanding.”

But Judge Kavanaugh’s role in the investigation of Mr. Clinton’s affair with a White House intern, which resulted in his impeachment in 1998, has raised a red flag among some people close to Mr. Trump. At a minimum, his views about when to impeach a president are sure to come up during a Senate confirmation hearing and would allow Democrats to shine a spotlight on Mr. Trump’s handling of the Russia investigation.

Judge Kavanaugh, who after working for Mr. Starr served as an aide to President George W. Bush, has since expressed misgivings about the toll investigations take on presidents. In 2009, he wrote that Mr. Clinton should have been spared the investigation, at least while he was in office. Indicting a sitting president, he said, “would ill serve the public interest, especially in times of financial or national-security crisis.”

White House officials said Mr. Trump was aware of Judge Kavanaugh’s views, but they played down the effect on his candidacy. While some people close to Mr. Trump said Democrats could try to exploit his Clinton-era statements, they did not believe this issue would torpedo his chances of getting the nomination.

Mr. Trump’s advisers urged him to make a final decision on his choice for the court before he left Washington on Thursday morning for Montana, so they could begin preparing a rollout of the nomination, complete with a prime-time address. But several said they had resigned themselves to the likelihood that Mr. Trump would change his mind several times before Sunday.

“We fully expect the Senate will find the president’s choice to have the qualifications, intellect and temperament to serve in the Supreme Court,” said a deputy press secretary, Raj Shah.

As a Yale Law graduate in his early 30s, Judge Kavanaugh was one of the primary authors of Mr. Starr’s report to Congress, which said Mr. Clinton had lied under oath and concealed evidence of his relationship with an intern, Monica Lewinsky.

The report laid out 11 possible grounds for impeachment, two of which are drawing scrutiny in the context of the investigation by the special counsel, Robert S. Mueller III, who is looking into whether Trump associates aided Russia’s interference in the 2016 election — in an investigation that has been expanded to include whether the president tried to obstruct the inquiry itself.

First, the Starr report said that Mr. Clinton lied to his aides about his relationship with Ms. Lewinsky, “knowing that they would relay those falsehoods to the grand jury.” Second, it said he lied to the American public, and that senior officials, including the press secretary, then relied on those denials in their own misleading public statements.

“The president’s emphatic denial to the American people was false,” the prosecutors wrote. “And his statement was not an impromptu comment in the heat of a news conference. To the contrary, it was an intentional and calculated falsehood to deceive the Congress and the American people.”

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Judges Amy Coney Barrett, Brett Kavanaugh and Raymond Kethledge are among the frontrunners to replace Justice Anthony Kennedy. Here’s a look at some of their remarks about reproductive rights.

By that standard, Mr. Trump’s misleading statements to the news media, his miasma of tweets and his protracted public debate over whether to speak with Mr. Mueller could all be used against him, even if the special counsel declines to accuse the president of obstruction of justice.

The Starr report faulted Mr. Clinton for refusing six invitations to testify before a grand jury, saying the refusals substantially delayed the investigation. Mr. Trump has been debating for months whether to accept Mr. Mueller’s invitation to give an interview, and his lawyers have argued against it. Under the standard set by the Starr report, Congress should consider that as potential grounds for impeachment.

Mr. Trump also personally dictated a misleading statement to The New York Times about a secret meeting that his son arranged with a Russian lawyer at Trump Tower during the 2016 presidential campaign. Mr. Trump’s lawyers and the White House press secretary, Sarah Huckabee Sanders, then repeatedly and falsely denied that Mr. Trump dictated the statement.

The Starr report faulted Mr. Clinton for turning his press secretary and other White House officials into “unwitting agents of the president’s deception.” It named four aides — John Podesta, Erskine Bowles, Sidney Blumenthal and Harold Ickes — whom it said were lied to by Mr. Clinton about Ms. Lewinsky and who repeated those falsehoods to a grand jury.

The House ultimately did not adopt these two grounds when it voted to impeach Mr. Clinton. But Judge Kavanaugh’s involvement in drafting them creates the possibility that Democrats would try to make his confirmation hearing a referendum on the standards of impeachment. And it would force the White House to talk about the Russia investigation during what would otherwise be a welcome reprieve.

Colleagues of Judge Kavanaugh said they did not recall whether he pushed for these two passages to be included — or if he resisted them. They noted that there was lively debate on Mr. Starr’s team about what to include in the report, but that in the end, it was the independent counsel’s call.

“I don’t think it’s a fair conclusion to draw that everyone’s name who appeared on the report agreed with everything written there,” said Andrew D. Leipold, one of Judge Kavanaugh’s co-writers, who is now a law professor at the University of Illinois College of Law.

“Our job was to emphasize the grounds for impeachment,” he added. “We’re not the decision maker; Congress is the decision maker.”

Another of Judge Kavanaugh’s co-writers, Julie Myers Wood, said the decision on how to define obstruction of justice was made by more senior members of the team.

“It was not my recollection that any of us were the thought drivers on obstruction,” said Ms. Wood, who now runs an investigative firm. “The seasoned and experienced prosecutors were the ones driving what was reasonable in terms of obstruction.”

Some legal experts said the broad language in the Starr report merely reflected a recognition that impeachment is a political, not a legal, judgment. “Lying to the American people might be impeachable, but it might not be a crime on the statute books,” said Akhil Reed Amar, a professor of law and political science at Yale University.

Mr. Amar, who supports Judge Kavanaugh, said the judge’s misgivings about the Starr investigation were welcome evidence of maturity. “I’d rather have someone who has experience and has made mistakes than someone with no track record of difficult decision making,” he said.

In rethinking his views, Judge Kavanaugh wrote in 2009 in the Minnesota Law Review that Congress should pass laws that would protect a president from civil and criminal law suits until they are out of office. In any event, he said, there was always a way to remove a “bad-behaving or lawbreaking President.”

“If the president does something dastardly,” he wrote, “the impeachment process is available.”

Maggie Haberman contributed reporting from New York, and Michael S. Schmidt and Adam Liptak from Washington.